There has been a substantial increase in the number of data centers, which may be defined as locations, for instance, rooms that house computer systems arranged in a number of racks. The computer systems are typically designed to perform jobs such as, providing Internet services or performing various calculations. In addition, data centers typically include cooling systems to substantially maintain the computer systems within desired thermodynamic conditions.
The power required to transfer the heat dissipated by components, such as, computer systems, in the racks to the cool air contained in the data center is generally equal to about 10 percent of the power needed to operate the components. However, the power required to remove the heat dissipated by a plurality of racks in a data center is generally equal to about 50 percent of the power needed to operate the components in the racks. The disparity in the amount of power required to dissipate the various heat loads between racks and data centers stems from, for example, the additional thermodynamic work needed in the data center to cool the air. In one respect, racks are typically cooled with fans that operate to move cooling fluid, for instance, air, conditioned air, etc., across the heat dissipating components; whereas, data centers often implement refrigeration cycles to cool heated return air. The additional work required to achieve the temperature reduction, in addition to the work associated with moving the cooling fluid in the data center and the condenser, often add up to the 50 percent power requirement. As such, the cooling of data centers presents problems in addition to those faced with the cooling of the racks.
Conventional data centers are typically cooled by operation of one or more computer room air conditioning (CRAC) units, which consume relatively large amounts of energy. In some instances, conventional CRAC units do not vary their cooling fluid output based on the distributed needs of the data center, but instead, these CRAC units generally operate at or near a maximum compressor power even when the heat load is reduced inside the data center. In other instances, the CRAC units are operated based upon the time of day or the current demand level. Consequently, conventional cooling systems often incur greater amounts of operating expenses than may be necessary to sufficiently cool the components contained in the racks of data centers.